Compact disks were originally designed as a storage/reproduction medium for the digital recording of music. Disks created for this purpose utilize a plastic-coated, aluminized surface having a standard diameter measuring 4.72 inches (12 cm.) and a standard thickness of 1.2 mm. Mini disks have a standard diameter measuring 8 cm. And a standard thickness of 1.2 mm. Audio information is generally placed on only one surface of the disk in digital form as a track of microscopic pits in the thin, reflective aluminum layer. It is the spacing and length of these pits, each being about 1 micron in length, which determines what data the disk player unit “sees”.
In order to “play” such a disk, a beam from a semiconductor laser is focused upon the pits through a series of lenses and prisms. Light striking a pit is scattered whereas light hitting the smooth surface between pits is reflected back to a prism through a photo-detector, i.e., a diode, that converts light into an electronic signal. The resultant on and off digital signal is then decoded and fed through an electronic filter, thus converting it from digital form into an analog signal suitable for any hi-fi amplifier.
Audio compact disc technology of the type described above has been combined with a computer application in order to create an optical storage system known as the CD-ROM (compact disc, read only memory), utilizing either the standard 4.72 inch compact disk. Each CD-ROM can store over 700 megabytes of information. A DVD holds a minimum of 4.7 gigabytes of data, enough for a full-length movie.
Blank optical discs are constructed of a layer of a heat-sensitive metal film, an organic polymer (e.g., a plastic) or a combination of both, deposited upon an a plastic substrate. Optical recording techniques deposit digital information upon the surface of the disc by marking this surface in a number of fashions. These techniques include: ablative recording, in which a laser creates a series of pits in the coating layer; bubble forming, in which the laser's heat generates a tiny volume of gas in the underlying polymer, which becomes trapped and thus forms a bubble in the surface of the metal film layer; and crystalline to amorphous phase change, in which the reactive layer of the disc is changed from light-reflecting to transparent by the writing laser.
A protective plastic or lacquer coating on the surface of the CD, CD-ROM, CD-RW or DVD prevents dust or debris from reaching its reflective metal surface. Only significant scratches, gouges or blemishes can interfere with the laser light beam causing a degradation of the stored sound, data or picture.
One common cause of such damaging scratches, gouges and/or blemishes is the removal and/or insertion of laser disk devices of the type described above from or into, respectively, a molded plastic storage case of the type commonly used to hold such disks. These cases contain many sharp edges which, if a disc is carelessly handled, can scratch or gouge the information-bearing surface of the disk and thus result in a loss of some or all of the information contained thereon.
Typical example of such a storage containers are disclosed in U.S. Pat. No. 4,535,888 to Nusselder and U.S. Pat. No. 5,383,553 to Lammerant, et al. These references describe plastic cases suitable for the storage of CD, CD-ROM, CD-RW or DVD disks having high information storage density. Storage cases constructed in this manner are commonly referred to as a “jewel-box” or “jewel case” due to their hinge-type construction consisting of two shallow trays. One tray is intended to hold the CD record whereas the other tray acts as a cover which can be swung open to provide access to the disk, and swung closed to enclose and protect the record. This type of case has a number of drawbacks. It is relatively expensive to manufacture, as well as being subject to breakage due to the fragility of the hinge. Also, it is sometimes hard to open by the elderly and young.
To overcome these disadvantages, various types of slidable-component cases were devised, involving drawers which slid into flat enclosures that had edge openings for this purpose. One patent revealing this drawer-type case is U.S. Pat. No. 5,011,010. However, the proposed construction in this patent was still costly to produce, and had other drawbacks such as the likelihood of breakage and/or malfunction.
A sliding drawer type case is also disclosed in U.S. Pat. No. 4,463,849. The construction shown here is similarly prone to malfunction and breakage, as well as improper reassembling of separable parts and warpage due to the thinness of plastic sections.
U.S. Pat. No. 4,609,105 discloses a sliding drawer type CD case having generally the same drawbacks as already listed above, namely high cost, lack of durability, inconvenience and likelihood to malfunction.
A hinge-and-slide type of CD case is shown in U.S. Pat. No. 5,263,580. The construction and functioning are more complex than with the above-described cases, and in consequence the likelihood of breakage and malfunction is increased, as well as the cost of producing the units.
A sliding cover case is disclosed in U.S. Pat. No. 5,511,659. This case requires a nest formation to receive and hold a compact disk. The base and cover members of the case have cooperable slide mounting means on the base and at least one cover member to facilitate opening and closing of the case. Tracks on the base and cover members are disclosed.
Slidable component cases were devised to overcome many of the mechanical weaknesses of jewel cases such as easily broken hinges. The slidable cases retained the nest piece used to position and hold the disk in place. Ironically, this nest piece, which is intended to protect the disk by holding it immobile, poses the greatest risk for causing damage to the disk. The sharp edges of the hard plastic central spindle and peripheral disk supports can easily scratch and gouge a disk surface as the disks are removed from or replaced in the nest.
The above drawbacks and disadvantages of prior CD and DVD disk cases or packages, such as hinged jewel cases and sliding cover cases and the like, are obviated by the present invention. The present invention provides a novel and improved, hinge less CD/DVD case which is especially durable and not likely to malfunction or become easily broken, as with existing hinged CD or DVD cases and does not require a nest or central spindle to secure and hold the CD or DVD or the like in place.
The inventive case provides an improved CD or DVD disk case as above set forth, which is commensurate in size with existing larger hinged cases generally used for DVD storage such that it can be accommodated in the usual racks designed to accommodate such DVD cases now being used, to hold the present large CD or DVD disk cases.
The inventive case does not require a nest to hold the disk. A nest is known in the art as a recessed area having the same diameter as a disk. The disk sits in the nest and is thereby held immovable within the disk case.
The inventive case provides increased surface area for written and promotional material to be placed on both cover members as well as the inside and outside of the base plate. The inside of the base plate is not available for written and promotional materials in disk cases having a nest.
The inventive case provides an improved disk record case as above described, which is especially easy to open and simple to operate with regard to removal and replacement of the disk.
Still other features of the invention reside in a hinge less disk case which has nibs to control the movements of slidable cover members, a case which always can lay perfectly flat when either open or closed, a case constituted of plastic and not requiring a nest or support means to immobilize and protect the disk.
Still another feature of the case is its ease of assembly. The two cover can be easily snapped down over the base then slid closed. Once assembled, the case resists disassembly. Other features and advantages will hereinafter appear.